Continuous process of shrinkproofing wool with alkali metal salts of dichlorisocyanuric acid



Jan. 21, 1969 c. TREZAIN ETAL CONTINUOUS PROCESS 0F SHRINKPROOFING WOOL WITH ALKALI METAL SALTS OF DICHLORISOCYANURIC ACID Filed June 21, 1963 a o s R R Y NA E TM N s R VR T m m A E W D A A lv L B CN United States Patent 3,423,164 CONTINUOUS PROCESS OF SHRINKPROOFING WOOL WITH ALKALI METAL SALTS OF DI- CHLORISOCYANURIC ACID Claude Trezain, Bois-Colombes, and Jean Claude 'Cosnard, .Iuvisy-sur-Orge, France, assignors to Compagnie de Saint Gobain, Neuilly-sur-Seine, France Continuation-impart of applications Ser. No. 152,640, and Ser. No. 152,641, Nov. 15, 1961. This application June 21, 1963, Ser. No. 289,497 US. Cl. 8127.6 10 Claims Int. Cl. D06m 3/20 This application is a continuation-in-part and improvement on the invention of application Ser No. 152,640 filed Nov. 15, 1961 with foreign priority and on that of application Ser. No. 152,641 filed Nov. 15, 1961, now Patent No. 3,144,300, Aug. 11, 1964, with foreign priority.

This invention concerns the treatment of keratinous textile fibers to prevent or minimize felting and shrinking, as do the former cases, but those cases had to do with what we shall call batch processes which were less than satisfactory when applied continuously. In industry it is advantageous, whenever possible, to carry out processes continuously and this is particularly true where textile materials, such as bolts of cloth, are being treated.

An object of the present invention is to adapt the processes of the prior cases to the continuous manufacture of cloth and to webs ofkeratinous material, and to carry out anti-felting and anti-shrinking treatments by moving lengths of continuous keratinous material, such as thread, in succession through the treating baths.

The prior processes used solutions which imparted to keratinous textile fibers an excellent resistance to felting and shrinking, but at the same time it offered the inconvenience of immobilizing the fabric for lengths of time which varied from a few tens of minutes to several hours. Coordination of the different baths to produce an equal time of treatment in each bath was quite difficult, so that the timing of the process was dependent on the slowest of the treatments. The treatment of materials in bulk also introduced problems of uniformity of result. Consequently, although the results were superior to those produced by known processes the method was curbed in its utility by such limitations.

It is an object of the invention to adapt that process to continuous operation. In obtaining the object it was found that such solutions are not themselves adapted to a continuous process, being slow and requiring bulk handling of goods. The concentration of the solutions tended to vary as the process was drawn out, a tendency to variation in the concentration of active chlorine in the baths ocuurred, producing some inequality of treatment.

This invention was made to overcome the difficulties of using aqueous solutions of the alkali metal salts of N-N dichloroisocyanuric acid in a continuous process of imparting non-shrinking and non-felting properties to keratinous fabrics.

The objects of the invention were accomplished, generally speaking, by a method of treating keratinous textile fibers against felting and shrinking which comprises immersing the keratinous material in an aqueous bath containing an effective amount of an alkali metal salt of N-N dichloroisocyanuric acid and a surfactant at a temperature of about 5 to 35 C., passing the material through an aqueous acid bath at a pH of about 1.5 to 5, passing the material through a dechlorinating bath, and washing and drying the material.

According to one characteristic of the present invention the pH of the bath is maintained at about 5.5 to 6 and the concentration of the alkali metal salt of the dichloroisocy- 3,423,164 Patented Jan. 21, 1969 anuric acid varies between 20 and grams per liter. Another characteristic of the invention is that the bath is maintained at a temperature between 5 and 35 C., which is conveniently cool.

These aqueous solutions are usually more concentrated than those contemplated in the prior applications, but that concentration is not harmful if the process is carried out under the other conditions set forth herein. The aqueous solutions are, surprisingly, very stable and can be maintained with a substantially constant content of active chlorine. Throughout the process, which climates the irregularities which have heretofore been found in attempting to use a continuous process, the quality of resistance to felting and shrinking is acquired by the fiber in the solution very swiftly, immersion from 5 to 30 seconds being usually adequate and 6 to 20 seconds being quite satisfactory in almost all cases. In the fact, the reaction is so fast that substantial and determinable results may be secured in from 2 to 3 seconds. The keratin of the fibers, when treated in accordance with the principles of this in Vention, are not deleteriously altered.

It has had particularly beneficial effects to add to the aqueous solutions of this invention a surface active agent to increase the speed of penetration of the solution into, and the wetting of the fiber. To this end one may use nonionic agents, anionic agents or cationic agents which are stable when they are in the baths of this invention. The surface active agents used did not appear to have any influence on the stability of the solution or on the results of the treatment. Among such agents there may be named the nonionic condensate of ethylene oxide and lauryl alcohol, the anionic agents of the type of sodiumoleocetylsulfate and the cationic agents lauryldimethylbenzylammoniumchloride or bromide are exemplary. These agents lower the surface tension.

After the short treatment with the principal solution, the cloth is passed through a series of treatments which complete the operation. These usually are an acidification, a dechlorination, rinsing and drying. The order in which these steps occur may vary.

The drawing illustrates apparatus and process which has been used successfully. The apparatus is schematic-ally shown and is composed of a series of vats with drums which serve to pass the keratinous material from vat to vat. A roller of keratinous goods unwinds to a drum in a first vat A, which contains the isocyanuric acid salt and, preferably, a surfactant. The vat B contains an acidifying solution, vat C contains a dechlorihation solution, and the vat D contains a washing solution. The cloth passes from drum to drum to the dryer.

The drawing is schematic and constitutes a flow sheet, as it illustrates the progress of the cloth from bath to bath. In general, it is advisable that the apparatus should wholly or largely eliminate the transference of liquid from bath to bath in order to prevent contamination. This is an old step which is carried out habitually by drying rollers, or suction apparatus which is applied to the cloth in each vat before they proceed to the following vat. Such apparatus is not shown in the drawing, being known.

To carry out the acidification, one may use any usual mineral or organic acid in water solution, the pH being usually between 1.5 and 5 according to the particular operating condition. Ordinary mineral acids are satisfactory and there is no reason of cost to depart from them, for instance HCl. The dechlorination vats contain standard solutions of dechlorinating agents, such as sodium bisulfite or sodium hydrosulfite, which are cheap and effective. Other standard dechlorination agents can be used but do not have increased effectiveness. The concentration will vary according to the particular agent used. When sodium bisulfite is used the concentration is usually between 2 and 20 grams per liter.

According to the type of apparatus employed, the speed of cloth through the baths will vary within rather large limits, but good results can be obtained at a linear velocity between about .5 and meters per minute. As stated, in treatments involving successive immersion in the baths the immersion may vary in practice between 1 second and 1 minute. For example, in an industrial operation, for reasons of economy, the speed will take the cloth through each bath in from 5 to seconds. In ordinary practice immersion times between 6 and 20 seconds are adequate for a complete, satisfactory treatment. Nonetheless, treatments of immersion lasting only 3 seconds have produced substantial and determinable results. The washing baths are standard and may, for example, contain a quaternary ammonium halide solution as well as anionic washing agents.

The process of the invention is particularly adapted to the treatment of webs of keratinous textile fibers, such as carded wool, to ribbons of keratinous flock, to thread, felted fabric, knitwear and to mixed goods containing keratinous material.

The following examples are merely illustrative and do not derogate from the generality elsewhere stated herein. In the following examples, the material used was carded wool from Australia of meters to the kilogram, quality 100/105 having a mean diameter of 21.55 microns. The treatment was carried out in an apparatus such as is schematically illustrated in the drawings.

Example I Each vat contains a perforated drum which is partly submerged in the liquid and rotates around its axis. The fabric is carried by the drum. In order to insure complete and homogeneous impregnation, the drums may be evacuated to cause a flow of the liquid through the cloth, the liquid being ejected from the part of the drum which is above the liquid level. This is not illustrated because it is not a part of the invention and has been used in other processes. At the downstream end of each vat there are preferably two rubber rollers, between which the fabric passes, which remove the solution from the fabric. This discharge can take place inside or outside the vat. The pressure on these rollers produce a substantially complete removal of entrained solution. Each vat is provided with sources of supply A, B, C and D, which maintain the level of the concentration of each liquid. For example, the vat A contained an aqueous solution of 40 grams per liter of sodium N-N dichloroisocyanuric acid and 1 gram per liter of the condensation product of ethylene oxide and lauryl alcohol. The pH of 6.4 was inherent. The surface active agent was made from 9 moles of ethylene oxide and 1 mole of lauryl alcohol. The volume of the bath was maintained constant by a supply of the same solution delivered from source A. The consumption was 1 liter per kilogram of fabric treated.

The second vat contained an aqueous solution of 1.5 cc. per liter of 20 B. HCl. Reserve supply B contained 15 cc. per liter of the same acid. The discharge of the reserve solution into the vat showed a consumption of 330 cc. of the reserve per kilogram delivered. The pH of the bath remained at about 2.

The third vat contained 5 cc. per liter of 36 sodium bisulfite. The corresponding reserve vessel contained a solution of cc. per liter of 36 B. sodium bisulfite. The discharge of the reserve solution into the vat showed a consumption of that solution of 900 cc. per kilo-gram of material treated. The pH of the solution was self-stabilized at a value near 3.

The fourth vat was directly connected to a source of water supply and the consumption of water was 30 liters per kilogram of fabric treated. The washed fabric was dried on a drum and the dried product was tested according to a standard anti-felting and anti-shrinking test. The untreated sample shrank 54.7%; the sample treated ac- 4 cording to Example 1 shrank 11.9%. The material had a fine soft touch and did not undergo any yellowing.

Example II The sheet of cloth was treated in a washer at 3 meters per minute and was passed into the first vat, which contained an aqueous solution of sodium N-N dichlorocyanuric acid at grams per liter and a surface active agent made by condensing 9 moles of ethylene oxide with 1 mole of lauryl alcohol at one gram per liter. The pH was 6.4. The volume of the bath was maintained by the contents of the reserve supply. The consumption of reserve solution was one liter per kilogram of material treated. The second vat contained an aqueous solution of 2 cc. per liter of 20 B. HCl. The reserve supply contained an aqueous solution of 25 cc. per liter of the same acid. The flow of reserve solution into the vat was regulated so that the consumption was 1000 cc. of reserve solution per kilogram of fabric treated. Under these conditions the acidity of the bath remained constant at about pH 2. The third vat contained an aqueous solution of 5 cc. per liter of 36 B. sodium disulfite. The reserve supply for this vat contained a solution of 60 cc. per liter of the same 36 bisulfite. The discharge of this solution into the vat took place at a rate of 450 cc. of reserve solution per kilogram of material treated. The pH of the solution in the vat Was about 2.

The fourth vat was directly connected to a source of water supply. The consumption of water corresponded to 30 liters per kilogram of material treated. The material was dried by the passage over a heated rotating drum.

The treated fabric was tested and yielded the following results: The untreated fabric shrank 54.7%, the treated fabric shrank 22.8%. The material had a good hand and did not undergo yellowing.

By maintaining the concentrations and times within those which have been stated hereinabove, it is possible to obtain excellent and even superior shrinking and felting resistance by a continuous process. This enlarges the utility of the process described in the identified applications, and accomplishes the objects of the invention.

As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments.

What is claimed is:

1. A method of treating keratinous textile material against shrinking and felting which comprises passing the textile material progressively through an aqueous, concentrated solution containing between about 20 and g./l. of an alkali-metal salt of N-N dichloroisocyanuric acid at about neutral pH, and through an acid bath of pH between about 1.5 and 5.

2. The process described in claim 1, in which the treatment of claim 1 is followed by dechlorination, rinsing and drying.

3. The process according to claim 1, in which the bath is at about neutral pH and contains about 20-100 grams per liter of the alkali metal salt of N-N dichloroisocyanuric acid.

4. The process according to claim 1, in which the temperature of the bath is between 5 and 35 C.

5. The process according to claim 1, in which the bath contains a surface active agent which may be of anionic, nonionic or cationic type.

6. The process of claim 1, in which the textile material is immersed in the bath between about 5 and about 30 seconds.

7. A method of treating keratinous material against felting and shrinking which comprises passing the keratinous material progressively through an aqueous bath containing between about 20 and 100 g./l. an effective amount of an alkali metal salt of N-N dichloroisocyanuric acid and a surfactant at a temperature of about 5 to 35 C., passing the material through an aqueous acid bath at a pH of about 1.5 to 5, passing the material through a dechlorinating bath, and Washing and drying the material.

8. A method of treating keratinuous material against felting and shrinking which comprises: maintainingan aqueous bath containing between about 20 and about 100 g./l. of an alkali-metal salt of N-N dichloroisocyanuric acid, and a surfactant, at a temperature of about 5 to about 35 C., maintaining an aqueous acid bath at a pH of about 1.5 to about 5, maintaining an aqueous dechlorinating bath at a concentration equivalent to about 2 to about 20 g./1, of sodium bisulfite, passing keratinous material through the baths in succession at a rate between about .5 and about 15 meters per minute, washing the keratinous material, and drying it.

9. A method of treating keratinous material against shrinking and felting which comprises: preparing and maintaining an aqueous bath containing about 40 g./l. of alkali metal N-N dichloroisocyanuric acid, about 1 g./l. of ethylene oxide-lauryl alcohol reaction product at about neutral pH, at a temperature between about 5 and about 35 C., preparing and maintaining an aqueous bath containing about 1.5 cc./l. of 20 B. HCl at a pH about 2, preparing and maintaining an aqueous bath containing about 5 cc./ 1. of 36 B. alkali metal acid sulfite, passing a length of keratinous material in succession through the baths, washing the material in Water, and drying it.

10. A method of treating keratinous material against shrinking and felting which comprises: maintaining an aqueous bath containing about 80 g./l. of alkali metal N-N dichloroisocyanuric acid, about 1 g./l. of ethylene oxide-lauryl alcohol reaction product at about neutral pH, at a temperature between about 5 and about C., maintaining an aqueous bath containing about 2 cc./1. of 20 B. HCl at a pH about 2, maintaining an aqueous bath containing about 5 cc./l. of 36 B. alkali metal acid sulfite, passing a length of keratinous material in succession through the baths, washing the material in Water, and drying it.

References Cited UNITED STATES PATENTS 3,144,300 8/1964 Cosnard et a1. 8-127.6 3,184,285 5/1965 Bitterli 8127.6

FOREIGN PATENTS 219,930 1/ 1959 Australia.

NORMAN G. TORCHIN, Primary Examiner.

I. C. CANNON, Assistant Examiner.

US. Cl. X.R. 

1. A METHOD OF TREATING KERATINOUS TEXTILE MATERIAL AGAINST SHRINKING ANMD FELTING WHICH COMPRISES PASSING THE TEXTILE MATERIAL PROGRESSIVELY THROUGH AN AQUEOUS, CONCENTRATED SOLUTION CONTAINING BETWEEN ABOUT 20 AND 100G./L. OF ALKALI-METAL SALT OF N-N DICHLOROISOCYANURIC ACID AT ABOUT NEUTRAL PH AND THROUGH AN ACID BATH OF PH BETWEEN ABOUT 1.5 AND
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